Conventionally, most content data provided through the Internet were small size data such as document or picture. However, as data transmission technology and devices develop, multimedia contents are also widely provided. The multimedia contents are transmitted to user clients through the streaming method.
Conventionally, streaming data were transmitted from one server to user clients.
The streaming data should be transmitted in real time. However, as the streaming data were transmitted from one server to user clients conventionally, transmission delay has occurred frequently when load of the server becomes higher or connection state is unstable. Because the streaming data should be played as soon as they are downloaded, transmission delay affects QoS (Quality of Service) greatly unlike general file download.
As a prior art regarding file download, U.S. Pat. No. 6,339,785 discloses a method for downloading files through multiple servers. According to the U.S. Pat. No. 6,339,785, total file is divided by N and file is downloaded through N servers so that file can be transmitted stably although error occurs in one connection.
However, according to the above file download method, the file is available only after whole data are downloaded. Therefore, the download method of U.S. Pat. No. 6,339,785 can not be applied to streaming data that should be played as soon as they are downloaded.